Switch



- high resistance, poor connections,

. a definite eflort on the j tuating'the switch to move the same betweenits Patented May 4,

Edward N. Jacobi, Milwaukee, Wis, assignor a; i Brian at StrattonCorporation, Milwaukee,

Wis.',acorporation ofllelaware Application July 11, 1940, Serial No.682,730

This invention relates to electric switches and s Claims. (01. zoo-15:

refers more particularly to lock switches of the type having a contactorrotatable across the face i of a terminal head toward and fromengagement with stationary contacts on the terminal head to place theswitch in on-' and of? positions.

It is customary to provide a certain amount of contact pressure betweenthe circuit making contacts of any electric switch so that theresistance across the contacts will be kept to a minimum.

The accompanying drawingillustrates one complete example of the physical:embodimentof the invention constructed in accordance with the best modeso far devised for the practical application of the principles thereof,and in which:

Figure -1 is a side elevation of an ignition-lock switch of the typeused in automobiles and the like Such contact pressure is particularlydesirable in lock switches designed for automotive use since without itthe vibration normally attendant upon operation of the vehicle tends tocause intermit tent separation of the contacts with resultant and arcingacross the contacts. It is also particularly desirable that switches ofthe rotary contactor type have a strongly marked detent actioncomparable to that of conventional quick break snap switches,

the advantages of which are well known. A quick break snap action is afeature of Special im-- portance in an automotive ignition lock switchinasmuch as it assures positive switch action. and especially since thedriver of a motor car seldom gives much attention to the act of turningthe ignition switch "on" and o i It is, therefore, an object of thisinvention to provide a rotary contactor type electric switch of thecharacter described with a strongly marked detent action by which snapaction of the switch is produced.

Another object of this invention resides in the provision of novel meansin a rotary electric switch ofthe character described for efiectingacceleration of contact separation so that tuming 05" of the switchcauses a quick breaking of the contacts with a snap action. Stillanother object of thisinvention resides in providing a rotary switch ofthe character described with simple detent mechanism requiring part ofan operator acmade as come within the scope of the claim.

position of the switch so as to produce with portions of the switch casebroken away and shown in section to illustrate the application of thisinvention thereto; and

Figure 2 is an exploded perspective view showing the component parts ofthe switch mechanism.

Referring now particularly to the accompanying drawing in which likenumerals indicate like parts, the numeral I designates enerally a lockswitch of the type designed for mounting on the instrument panel of anautomobile forthe control of the ignition circuit of the automobile.

The switch here shown comprises a casing 2 bored to rotatably receive anactuator, not shown, in the front portion of the case adjacentto thepanel upon which the switch is mounted. In a lock switch of the typehere shown the rotatable pin or plate tumbler cylinder constitutes theactuator for the switch. H r

The case 2 is provided with a counterbore 2' its rear portion to receivethe switch mechanism. Th switch mechanism includes a ter- I a positionclosing the mout minal plate 3 preferably formed from non-conductivematerial and disposed crosswise of the counterbore to close the rear ofthe casing.

The terminal plate is secured to the casing in h of the counterbore byless conventional practice the case over the back face means of the moreor of spinning the rear of of the terminal plate.

A plurality of stationary contacts 4 are carried by the terminal plateand are exposed at the inner face thereof to be substantially flushtherewith. Terminals 4' electrically connected with the stationarycontacts i 4 project rearwardly.

through the insulating terminal plate and extend from the rear thereofas shown to provide for the attachment of electrical conductors thereto.i

" The rotatable eontactor 5 of the switch. is in.

the form of a s ider in that it has a plurality of circumferentlallyspaced legs 6 each terminating in a foot I constituting the movablecontacts per se and adapted for iengagementqwith the .ment of thehereindisclosed. invention may be II stationarycontacts I on the innerface of the terminal plate.

The contactor'has its feetfl; normally engaged with the inner face .ofthe terminal plateand is adapted to be rotated thereacross: to establishor switch.

a they are struck so gageable with the to limit motion oi 3 g break thecircuit or. circuits controlled .by the The contactor I is operativelyconnected with an insulating disc 8 through which rotation is impartedto the contactor. The connection beassaeoo tween the contactor andinsulating disc com- .prises three circumferentially spaced legs 8 onthe contact spider remote from the contacts 1 thereof whic'li extendlongitudinally forwardly to slidably engagein mating apertures Ill inthe insulating disc. As will be readily seen, rotation of the insulatingdisc imparts rotation to the contact spider through the legs '9 thereofengaging in the apertures III in the disc while the insulating disc 8 isfree to slide along the legs 8 axially or the counterbore 2' a limiteddistance toward and from the contact spider. The legs 8 are offset withrespect to the body oi as to provide shoulders 8' enrear face of theinsulating disc the disc rearwardly in the counterbore toward thecontactor and terminal plate. The insulating driver or coupling by thenumeral l I.

disc 8 is in turn carried by a element designated generally The driveris freely rotatably the spider from which v '4 ably made as a separateunit and inserted into the case during flnal assembly of the switchmechanism. The cam 28 has its cam surface 28' facing rearwardly towardthebaclr or the case.

'lhree-circumferentiaily spaced trunnions II project from the sides ofthe forward end oi the driver on radial axes and rotatably mountcollar-liko cam rollers 22 the peripheries or which are maintained inengagement with the cam surface 28' by the compression spring l8 so thatthe cam determines the axial position of the driver in the switch case.It will also be noted that the thrust of the spring i8 is borne by thecam track and consequently the-casing, and that the shoulders 8" on thelegs 8 or the contactor hold the insulating disc 8 spaced inwardly orthe flanges ll on the driving legs It so that the full force of thespring is utilized to press the contactor against the inner face of theterminal p ate.

Prior to assembly of the switch mechanism in the switch case. the springI8 is first placed in the well formed between the legs it of the driver-I I. The insulator 8 is then set in place over the mounted in thecounterbore 2' between the con tact spider and the actuator for theswitch and has a substantially cylindrical body portion I: of a size toguide the driver for rotation and axial sliding motion in thecounterbore 2' on the axis,

thereof. A suitable axial non-circular hole I! in the forward end or thebody portion I2 is provided to receive a driving lug II on the, innerextremity of the actuator or lock cylinder so that the driver orcoupling element II is constrained to rotate with the lock cylinder whenthe latter is turned by means of a proper key it while being free toslide axially relative to the actuator and 0on tactor.

The driving connection between the coupling element and the contactor isprovided by a plurality or circumferentially spaced legs l8, in thepresent case three, extending rearwardly from the body portion '12 ofthe driver I I. The legs ii are spaced radially from the axis of thedriver and have a channel shaped cross section, with the flanges on thechannel facing inwardly to receive lugs ll on the insulating disc 8therebetween and thus constrain the insulating disc and the contactor torotation with the driver while permitting free sliding of the driver inthe case. i

A compression spring 18 conflned in the axial well formed between thelegs it of the driver ll reacts against the body portion I! of thedriver and the insulating disc 8 and consequently the contactor 8 toyieldingly urge the disc and contactor rearwardly toward the terminalplate and to urge the driver forwardly toward the frontpf the casing.

inwardly turned flanges it at the rear extremities of the driver legs l8prevent the insulator 8 spring by tilting the insulator and advancingtwo of its driving lugs l'l down the grooves of two of the driver legsl8, against the pressure of the spring l8 until the remaining lug mayclear the flange is on the third leg 18 whereupon the disc is againtilted to bring its remaining lug l1 under itsretaining flanse ll.

The flanges is then prevent the insulator .8

from being expelled from the legs II by the spring I8 and hold the, discconnected with the driver for assembly in the case as a unit.

If the cam track 28 has been made separately,-

it is next, pressed into the bottom of the counterbore 2' inthe switchcase from the rear. 'I'he cam rollers 22 are slipped onto the trunnions21 on the driver I I and the driver, together with the spring I! and theinsulator 8, assembled as aforesaid, is inserted into the counterbor'e2', with the .cam rollers 22 engaging the cam track 20, and the lug Itreceived in the hole it in the driver body portion l2.

The legs of the contact spide I are then slipped into the slots It inthe insulator 8, and the terminal plate 3 securedin place closing therear of nism in the casing and require the disc to be tilted forassembly in the driver well.

The spring 18, as stated, yieldingly urges the driver forwardly towardthe bottompf the counterbore 2' and such motion of the driver is limitedby an annular cam 20 pressed-into the bottom of the counterbore so as.to be flxed with respect to the case. The cam may be formed integrallywith the case if desired, but is preferthe case. This may beconveniently accom-' plished by spinning the rear rim of the case overthe rear edge of the contact plate, although any other suitable meansmay be employed to hold the terminal plate in place.

when the switch is in the oil position the rollers on the driver areseated in depressions," in the cam surface 20' as indicated in Figure 1and the contact feet I of the spider bear comparatively lightly againstthe inner face 3' of the terminal plate 3, but are not in contact withany of the stationary contacts 4. This condition is brought about by theaction of the spring l8 as hereinbefore pointed out. i

As the actuator or switch key is turned toward the switch 'fon"position, the cam followers 22 on the driver are caused to ride up oneside of humps 28 on the cam track, there being one hump for each of therollers. These humpscam the driver rearwardly toward the terminal plateand cause the spring I! to be compressed between the driver and theinsulator disc 8 thereby increasing the pressure of the contact spiderfeet I against the face I of the contact plate.

Just before the contact feet 'I are brought into complete engagementwith the stationary. contacts l, the cam rollers 22 move over the peaksof the humps and are caused to snap into depressions 21 at the oppositesides of the humps pressions 21 defines'the switch "on position whereinthe contact feet 1 of the contractor! are completely engaged with thestationary contacts 4; Continuedrotation oi the contractor at this timeis prevented ,by engagement of the cam'iollowers with abutments 28 onthe cam surfacesalongside the depressions 21.

Since the cam track 20 is considerably higher at the detent formingdepressions 21 than at the oiP' positions 25 of the track, the driver llmaintains the spring compressed between it and the disc 8 to hold thecontactor firmly pressed against the stationary contacts.

When the switch is turned toward offi' position, a definite effort isrequired to rotate the key l5 or other actuator and overcome the forcewhich the spring I8 exerts to hold the cam rollers 22 in the detentforming depressions 21 oi? the cam track and to move the rollers overthe peaks of the humps 26. Immediately after the rollers pass the peaksof the humps and before the con tacts are completely disengaged, thespring I8 rapidly drives the rollers down the inclined sides across therear of the case and provided with .a

plurality of stationarycontacts on the inner sur-,' face of the plate,and a movable contactor abutting said surface 01' the plateand'adapted'to be rotated into circuit making engagement with saidstationary contacts to "close" the switch, characterized by: a driverrotatable in the case and operatively connected between the actuator andcontactor so that said elements rotate'in unison,

said connections permitting the driver to slide axially in said borerelative to the actuator and contactor; cooperating cam means on thedriver and the case for translating rotary motion of the driver in adirection to effect closing of the of the humps and into seatingengagement in 1 the depressions 25 to produce an extremely rapid breakminimizing arcing of the contacts by the speed of their separation.

From the foregoing description taken in connection with the accompanyingdrawing, it will be readily apparent that this invention provides amechanism for a lock switch or other type of rotary switch whichproduces a snap action of the switch to insure rapid breaking oi thecircuit or circuits controlled by the switch.

What I claim as my invention is:

1. A switch of the type having a substantially tubular case, an actuatorrotatable in the front portion of said case, a fixed contact platedisposed across therear portion of said case and having a plurality ofstationary contacts exposed on the front surface of the plate at theinside of the case, and a movable contactor inside the case havingcontact means abutting the front surface of said plate, said contactorbeing adapted to be rotated toward and from an operative "switch closed"position in which its contact means engages the stationary contacts onthe plate, characterized by: a rotatable driver for the contactordisposed in the case between the actuator and contactor; a drivingconnection between the driver and the contactor by which thedriver isaxially slidable in the case relative to the contactor while the latteris constrained torotate with the driver; spring means reacting betweensaid contactor and driver tending to separate the same axially forpressing the contact means on the contactor into engagement with saidcontact plate; a splined driving connection between the driverandactuator; cooperating cam means on the driver and the case definingthe axial position of the driver and for translating rotary motion ofthe driver in a direction to carry the contactor toward "switch closedposition into an switch into movement of the driver toward the contactplate, said cam means providing a detent defining the closed" positionof the switch; and spring means reacting between the driver and the'movable contactor for urging the contactor against the contact platewith a pressure increasing with rotation of the driver toward switchclosed position, said spring meansalso acting through the driver toyieldingly maintain said cam means engaged and to supply detent pressureupon rotation of the driver to close the switch.

3. A driver adapted to be received within the tubular case of a switchof the character described for transmitting rotary motion of actuatingmeans accessible at the front of the case into rotation of a contactcarrier to bring the same into and out of engagement with stationarycontacts inside the case at the rear thereof, said driver comprising: abody; means on the body to guide the same for rotary and axial movementinside the tubular case; means at one end of the body substantiallyaxially thereof providing for the establishment of a splined drivingconnection between the driver and actuating means; a plurality oflongitudinally, extending driving arms spaced radially from the axisofrotationof said "body portion and extending from the opposite end of.the body. said arms being adapted to receive said rotatable contactcarrier between them and provide a driving connection between the driverand carrier permitting the driver to slide axially relative to thecarrier, the space between said arms forming substantially a well forreceipt of a compression spring to react between the body of the driverand the carrier by which pressure of the contact carrier, against thestationary contacts is secured; and rollers carried by said body Iportion for rotation on fixed axes normal to the axial rearwardmovementof the driver relative I to the contactor to compress saidspring means therebetween whereby said contact means is caused to engagethe contact plate with an increasing pressure upon actuationof thecontactor toward switch closed position; and means on the driverengageable vwith a part fixed with respect to the case with a detentaction upon rotaaxis of the driver and cooperable with cam means on thecase for governing theaxial position of the driver in the case.

4. A driver'adapted to be received within the tubular case of a switchof the character described for transmitting rotary motion of actuat ingmeans accessible at the front of the case into rotation of a contactcarrier to bring thesaine into and out of engagement with stationarycontacts inside the case at the rear thereof, said driver comprising: abody; means on the body to guide the same for rotary and axial movementinside the tubular case; means defining an axial non-circular hole inone end 01' the body cooperable with 9. lug on the actuator to provide asplined driving connection betweenthe actuator and driver; a pluralityof contactor driver arms spaced radially from the axis ofrotation ofsaid against the terminal plate.

body portion but integraltherewith and extending longitudinally from theopposite end of the body to provide for the establishment of a splineddriving connection between the driver and contactor of the switch;flanges on the outer extremities of said arms for limiting the amount ofrelativeeaxial motion between the driver and contactor, the spacebetween said arms substantially forming a well to receive a spring forreaction between the driver and contactor; and cam followers projectingfrom the sides of the body for cooperation with cam means on the case bywhich the axial position of the driver in the case is determined. I

5. A switch of the type having a bored case, a rotatable actuator insaid bore and accessible at the front of the case, a terminal plateextending across said bore remote from the actuator and having aplurality of stationary contacts on its inner face, and a contactor inthebore abutting said face of the terminal plate and rotatable towardand from engagement with said stationary contacts, characterized by: adriver for the contactor rotatable in the bore; separate splined drivingconnections between the driver and actuator and between the driver andcontactor whereby said driver 'and contactor are constrained to rotatewith the actuator with the driver free to slide axially in its bore;spring means reacting between the driver and contactor for pressing thecontactor against the terminal plate; and cooperating cam means on thedriver and the case through which the case receives the thrust of saidspring means and by which rotary motion imparted to the driver by theactuator in a direction' to engage the contactor with said stationarycontacts is translated into axial motion of the driver in a direction tocompress said spring 8 the case, a terminal plate extending across thebore .near the rear of the case and having a plurality of stationarycontacts. exposed on its means and increase the pressure of thecontactor 6. A switch of the type having a bored case, an actuatorrotatable in the bore and accessible from the front of the case, aterminal plate extending across the bore and having a plurality ofstationary contacts exposed on its inner face, and a contactor in thebore abutting said face of the terminal plate and rotatable toward andfrom engagement with said stationary contacts, characterlzed by: adriver for the contactor rotatable and slidable in said bore; a splinedconnection betweenthe actuator and driver constraining said driver torotate with the actuator but allowing axial sliding motion of the driverin said bore;

, means connecting said driver with the contactor for rotation therewithand for axial motion relainner face, and acontactorin the bore rotatableacross the inner face of the terminal plate toward and from engagementwith said stationary contacts thereon, characterized by: coupling meansinside the bore connecting the contactor with the actuator for rotationtherewith, said couplin means being slidable axially in the bore withoutdisruption of the rotatable driving connection which it aflords betweenthe actuator and contactor; cooperating means on the case and saidcoupling means for. translating rotation of the coupling means to carrythe contactor toward engagement with the stationary contacts into axialsliding motion 01' the coupling means toward the terminal plate: and acompression spring reacting between the coupling means and the contactorfor yieldingly urging the same against said inner face of the terminalplate, said spring being compressed by axial sliding motion of thecoupling means toward the terminal plate to increase the pressure of thecontactor against said inner face of the terminal plate upon rotation ofthe coupling means by the actuator to carry the contactor intoengagement with the stationary contacts.

8. A driver for transmitting rotary motion 2 from a lock mechanism in abore at the front of a lock switch case to a rotatable contactor in acounterbore at the rear of said case to carrysaid contactor into and outof engagement with stationary contacts on a terminal plate closing saidcounterbore at the rear of the case, comprising: a. substantiallycylindrical body portion adapted to be rotatably and axially slidablyreceived in the counterbore of said caseand having an axial non-circularhole at one end to receive a lug extending rearwardly from the lockmechanism to constrain said driver to rotate with said lock mechanismwhile permitting axial sliding tlve thereto; a spring exerting an axialseparating force between said contactor and said driver for pressing thecontactor against the terminal plate; and cooperating cam means carriedby the driver and the case and maintained in operative relationship withone another by said spring for receiving the thrust of the spring andfor camming the driver axially in a direction to increase pressure ofthe contactor against the terminal plate through said spring as thedriver is rotated toward the closed position of the switch, whereby thepressure of the spring acting on said cam means through the driver atthe time of driver rotation to carry the contactor out of engagementwith the stationary contacts effects acceleration of such rotarymovement of the driver to insure speedy separation of the contactor fromthe stationary contacts.

7. In a switch of the type having a a rotatable actuator in the bore atthe front of bored case, 1

motion of the driver relative to the lock mechanism; a plurality ofcircumferentially spaced arms extending longitudinally rearwardly fromthe periphery of said body portion and integral therewith, said armshaving their inner surfaces facing the axis of rotation of the driverprovided with longitudinal spline forming grooves to provide forrotation of the contactor with said driver while permitting the driverto slide axially with respect to the contactor, said arms cooperaing toform a well therebetween for the receipt of a coil spring for reactionbetween the driver and contactor; a plurality of trunnions projectingfrom the sides of said driver on radial axes normal to the axis ofrotation of the driver and integral therewith; and rollers looselyjournalled on said trunnions and adapted to cooperate with cam meansfixed with respect to said case to control the axial position of thedriver in the switch case. r

- EDWARD N. JACOBI.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

